An overview of substances present in Canadian aquatic environments associated with endocrine disruption

Numerous environmental contaminants have been associated with the ability to affect the endocrine status of animals and with the potential to elicit effects on individuals or populations in Canadian aquatic environments. Potential endocrine disrupting substances (EDS) consist of almost every class of environmental contaminants reported to date, including industrial chemicals, historical and current use pesticides, metals, and different classes of natural products. It has been difficult to establish cause-and-effect relationships with potential EDS for several reasons: i) the diversity of ways that chemicals can influence endocrine systems challenges efforts to characterize chemicals that can cause endocrine responses, ii) many responses in aquatic biota have been associated with complex mixtures where the causative agents remain unidentified, and iii) most literature information deals with mammalian studies using pure compounds so there is considerable uncertainty regarding extrapolation to aquatic species and efficacy of environmental concentrations. An overview of the literature on EDS, specific to exposure within Canadian aquatic environments, is presented to emphasize the diversity and complexity of chemicals capable of altering endocrine function.